Fluid & Electrolytes Made Incredibly Easy - Chapter 2

Electrolytes

Substances that, when in solution, seperate (or dissociate) into electrically charged particles called ions

Anions

are electolytes that generate a negative charge. IE: bicarbonate, chloride, phosphorus

Cations

are electrolytes that generate a positive charge. IE: calcium, magnesium, potassium, sodium

Electro-neutrality

the balance of positive and negative charges of electrolytes outside of the cell and within the cell.

Most electrolytes interact with ______ to maintain acid-base balances

Hydrogen ions

Sodium

Located outside of cells. Effect serum osmolarity and extracellular fluid volume. Helps nerve and muscle cells interact.

Serum Sodium normal levels

135-145 mEq/L

Hyponatremia

<135 mEq/L

Causes: syndrome of inappropriate antidiuretic hormone secretion

Hypernatremia

>145 mEq/L

Causes: Diabetes, fluid loss

Chloride

Located outside of cells. Helps maintain osmotic pressure (water-pulling pressure). Gastric mucosal cells need chloride to produce hydrochloric acid, which breaks down food into absorbable components.

Serum chloride normal levels

98-108 mEq/L

Hypochloremia

<98 mEq/L

Causes: prolonged vomiting

Hyperchloremia

>108 mEq/L

Causes: Hypernatremia (high sodium)

Calcium

Located outside of cell. The major cation involved in the structure and function of bones and teeth. Needed to: stabilize the cell membrane and reduce its permeability to sodium, transmit nerve impulses, contract muscles, coagulate blood, and form bone and teeth.

Total serum calcium normal levels

8.9 - 10.1 mg/dL

Hypocalcemia

<8.9 mg/dL

Causes: Acute pancreatitis

Hypercalcemia

>10.1 mg/dL

Causes: Hyperparathyroidism

Ionized calcium normal levels

4.4-5.3 mg/dL

Hypocalcemia

<4.4 mg/dL

Causes: Massive transfusion

Hypercalcemia

>5.3 mg/dL

Causes: Acidosis

Potassium

Within the cell. Plays an important role in cell excitability regulation, nerve impulse conduction, resting membrane potential, muscle contraction and myocardial membrane responsiveness, and intracellular osmolarity control.

Serum Potassium normal levels

3.5-5 mEq/L

Hypokalemia

<3.5 mEq/L

Causes: diarrhea, vomiting, diuretic therapy, excessive sweating

Hyperkalemia

>5 mEq/L

Causes: burns and renal failure

Phosphorus

AKA phosphate salts, are within the cell. Essential for energy metabolism. Combined with calcium, phosphate plays a key role in bone and tooth mineralization. Also helps maintain acid-base balance.

Serum Phosphates normal levels

2.5-4.5 mg/dL OR

1.8-2.6 mEq/L

Hypophosphatemia

<2.5 mg/dL OR

<1.8 mEq/L

Causes: diabetic ketoacidosis

Hyperphosphatemia

>4.5 mg/dL OR

>2.6 mEq/L

Causes: Renal insufficiency

Magnesium

Acts as a catalyst for enzyme reactions. Regulates neuromuscular contractions, promotes normal functioning of the nervous and cardiovascular systems, aids in protein synthesis and sodium & potassium ion transportation.

Serum Magnesium normal levels

1.5-2.5 mEq/L

Hypomagnesemia

<1.5